Semiconductor device and photorelay circuit

A semiconductor device, comprising:

• an element portion, the element portion including:
• a first electrode;
• a second electrode including a first electrode portion, a direction from the first electrode to the second electrode being along a first direction;
• a third electrode;
• a semiconductor member;
• and
• a first insulating member,
• a second direction from the third electrode to the first electrode portion crossing the first direction,
• at least a part of the first insulating member being between the third electrode and the semiconductor member,
• the semiconductor member including:
• a first semiconductor region of a first conductivity type, and
• a second semiconductor region of the first conductivity type,
• a second impurity concentration of the first conductivity type in the second semiconductor region being higher than a first impurity concentration of the first conductivity type in the first semiconductor region,
• the first semiconductor region including a first partial region, a second partial region, and a third partial region,
• the first partial region being between the first electrode and the third electrode in the first direction,
• a direction from the first partial region to the second partial region being along the second direction,
• the second partial region being between the first electrode and the second electrode in the first direction,
• the third partial region being between the second partial region and the second electrode in the first direction,
• a direction from a part of the third electrode to the third partial region being along the second direction,
• at least a part of the second semiconductor region being between the third partial region and the second electrode in the first direction,
• at least a part of the second semiconductor region being between the third electrode and the first electrode portion in the second direction,
• the first electrode portion being in Schottky contact with the semiconductor member,
• the element portion being a transistor configured to operate normally-ON.